From: eregontp@gmail.com
To: ruby-core@ruby-lang.org
Subject: [ruby-core:100175] [Ruby master Feature#15504] Freeze all Range objects
Date: Sat, 26 Sep 2020 13:21:01 +0000 (UTC) [thread overview]
Message-ID: <redmine.journal-87748.20200926132100.17@ruby-lang.org> (raw)
In-Reply-To: redmine.issue-15504.20190104031246.17@ruby-lang.org
Issue #15504 has been updated by Eregon (Benoit Daloze).
ko1 (Koichi Sasada) wrote in #note-11:
> Eregon (Benoit Daloze) wrote in #note-10:
> > Related, should Enumerator::ArithmeticSequence be frozen too?
>
> new ticket?
I filed #17195
----------------------------------------
Feature #15504: Freeze all Range objects
https://bugs.ruby-lang.org/issues/15504#change-87748
* Author: ko1 (Koichi Sasada)
* Status: Closed
* Priority: Normal
* Assignee: matz (Yukihiro Matsumoto)
----------------------------------------
# Abstract
Range is currently non-frozen. How about freezing all Range objects?
# Background
We froze some types of objects: Numerics (r47523) and Symbols [Feature #8906]. I believe that making objects immutable solves some kinds of programming difficulties.
`Range` is mutable at least when written as Range literal. So we can write the following weird program:
```ruby
2.times{
r = (1..3)
p r.instance_variable_get(:@foo)
#=> 1st time: nil
#=> 2nd time: :bar
r.instance_variable_set(:@foo, :bar)
}
```
In `range.c`, there is a comment (thanks znz-san):
```c
static void
range_modify(VALUE range)
{
rb_check_frozen(range);
/* Ranges are immutable, so that they should be initialized only once. */
if (RANGE_EXCL(range) != Qnil) {
rb_name_err_raise("`initialize' called twice", range, ID2SYM(idInitialize));
}
}
```
# Patch
```
Index: range.c
===================================================================
--- range.c (リビジョン 66699)
+++ range.c (作業コピー)
@@ -45,6 +45,8 @@
RANGE_SET_EXCL(range, exclude_end);
RANGE_SET_BEG(range, beg);
RANGE_SET_END(range, end);
+
+ rb_obj_freeze(range);
}
VALUE
```
# Discussion
There are several usages of mutable Range in the tests.
* (1) Taint-flag
* (2) Add singleton methods.
* (3) Subclass with mutable states
Maybe (2) and (3) are crucial.
Thanks,
Koichi
--
https://bugs.ruby-lang.org/
next prev parent reply other threads:[~2020-09-26 13:21 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <redmine.issue-15504.20190104031246.17@ruby-lang.org>
2020-08-07 6:12 ` [ruby-core:99507] [Ruby master Feature#15504] Freeze all Range object ko1
2020-08-07 11:21 ` [ruby-core:99511] [Ruby master Feature#15504] Freeze all Range objects eregontp
2020-09-25 8:49 ` [ruby-core:100130] " matz
2020-09-25 11:53 ` [ruby-core:100142] " ko1
2020-09-25 13:58 ` [ruby-core:100146] " eregontp
2020-09-25 15:09 ` [ruby-core:100149] " ko1
2020-09-26 13:21 ` eregontp [this message]
2021-01-26 20:52 ` [ruby-core:102258] " alex.wayfer
2021-01-26 21:04 ` [ruby-core:102259] " zverok.offline
2021-02-06 0:29 ` [ruby-core:102405] " alex.wayfer
2021-02-06 10:47 ` [ruby-core:102410] " zverok.offline
2021-03-06 21:16 ` [ruby-core:102760] " alex.wayfer
2021-10-22 14:31 ` [ruby-core:105752] " Eregon (Benoit Daloze)
2021-12-03 3:28 ` [ruby-core:106434] " ko1 (Koichi Sasada)
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